A memory device fabricated on a semiconductor chip has a plurality of sense amplifiers each designed to detect a slight difference between the potentials on two mutually associated bit lines connected to a plurality of memory cells which form parts of a memory array. Such a differential voltage appearing on the two bit lines is detected upon amplification by the sense amplifier. The two bit lines may consist of a mutually complementary bit lines. The amplified differential voltage is transferred to an output circuit for determination of a bit of data based on the transferred differential voltage.
However, a certain memory device of the type having a plurality of sense amplifiers electrically connected by a pair of shared output lines to the output circuit has a problem in that a current path is liable to be established between the shared output lines through an inactivated sense amplifier during amplification by an activated sense amplifier and, for this reason, the time duration necessary for access to a memory cell tends to be prolonged.
It is therefore a prime object of the present invention to provide an improved memory device which is free from the current path established between the shared output lines during each of the read cycles.